since the last international workshop in 1984, significant advances have been made in our understanding of the normal and pathological functions of the dentin/pulp complex. This prompted the leadership of the Pulp Biology Group (PBG) of the AADR/LADR to organize the second international workshop with the theme of the Pathobiology of the Dentin/Pulp Complex to be held at the University of North Carolina at Charlotte, N.C., May 26-29, 1991. The organizing committee, selected from the leadership of the PBG, identified three clinical and five major scientific areas and 25 oral and 30 poster presenters in ten countries. Five internationally recognized experts, not necessarily in dental research, will present their reactions to each session topic to all conferences. The objective of this workshop is to provide a forum in which advances in basic research are disseminated to the scientific community and correlated with clinical problems. The three clinical topics were chosen because of their high relevance to clinical practice: hypersensitive teeth, pulpal reaction to restorative procedures and traumatic injury of teeth and related root resorption. In these sessions basic researchers and clinicians will discuss the mechanisms and management of the selected clinical problems based on the results of recent research. Five scientific sessions were identified: In Session I dentin development, repair and abnormal dentinogeneses will be discussed in light of recently discovered biochemical and genetic contributions. Session II will deal with dentin reaction relating to the smear layer and odontoblasts with the aim of providing a comprehensive review of the role of the smear layer in clinical dentistry and the form and function of odontoblasts under stress. In session III the involvement of recently identified two antigen- presenting cells in the regulation of immune reactions of the pulp and the influence of interactions with constituents of the extracellular matrix in differentiation, proliferation and migration of cells of the pulp and repair following injury will be discussed. In Session IV the regulatory mechanisms of pulpal microcirculation during inflammation will be considered, neurogenic inflammation will be characterized and the role of various pulpal vascular receptors for inflammatory mediators will be defined. Session V will deal with the role of sensory functions. Characterization and distribution of recently identified peptidergic nerves and their role in inflammation as well as single C-fiber recording and changes in sensory nerves with aging will provide a comprehensive view of pulpal pain physiology. In the evening sessions the daily topics will be discussed with the aim of developing an informal dialogue and an intellectual exchange of information. The final session will be devoted to identify priorities for future PBG research. The proceedings of the workshop, which will contain the presented papers, reactor papers, evening discussions and future researcher priorities in pulp biology research, will be published within nine months of the workshop.